The invention is situated in the technical field of the automatic closure of frames and relates more specifically to an automatic machine for applying bendable pins. From DE 4405661 there is known a machine for applying nails with the aid of a driving-in system, wherein the nails are provided from a dispensing magazine and a detector is capable of signalling the absence of nails in the magazine.
Also known are various types of machine suitable for frames, one of which allows a plurality of bendable pins to be automatically applied to the mouldings of the frame to allow it to be closed with a piece of card. For that purpose, above a work station, which is advantageously an endless belt conveyor, a carriage can move in a longitudinal direction on rails. The carriage carries one or more stapling guns. Each gun is provided with a magazine of bendable pins, which magazine will obviously need replacing or refilling in the event of jamming or when the pins have been all been used. This involves manual manipulation, together with temporary stoppage of the machine. It is also possible to use a device for automatically reloading magazines, but that results in weighty and costly machinery. In addition, such machinery does not solve the problems associated with malfunctions in the operation of the guns. Such machines moreover use only one gun or a plurality of guns, each of which has one or more pins to apply at one or more predetermined locations. The user must therefore ensure that a constant visual check on the presence or absence of the pins is carried out. If a pin is absent, he must decide which gun is defective and then stop the machine and replace the gun. In addition to lost productivity, there is a risk of creating an unsatisfactory product.